RDA and alphabet soup

Philip J. Goscienski, M.D.

April 2013

If nutritional terms bearing initials such as RDA, DV, DRI, AI, ESADD, EAR and UL throw you for a LOOP you can blame the IOM of the USNAS. The IOM is the Institute of Medicine, a division of the United States National Academy of Sciences. The institute's purpose is to provide advice on a number of health issues, mostly for governmental and commercial groups, not for individuals.

The RDA, Recommended Dietary Allowance, is probably the most familiar term among the seven noted above but you won't find it on the nutrition labels that the government requires on all packaged food products. Instead, the DV (Daily Value) is listed as a percentage of the recommended amount based on a 2,000-calorie diet. That makes it an extremely rough guideline. For a hefty male athlete the percentage is low; for a sedentary, petite, elderly female it's high. The Daily Value will vary if you are a smoker or pregnant, or if you exercise almost every day at moderate to high intensity.

The RDA was developed more than 60 years ago as a set of guidelines primarily for military applications in hopes that it would cover the needs of most healthy persons. In the late 1990s it became only one component of the DRI, Dietary Reference Intake. The most useful component of the relatively new DRI might be the UL, which should stand for Upper Limit but that the experts unexplainably refer to as the Tolerable Upper Intake Level. The UL is the amount of any nutrient that should not be exceeded over the long term.

It all comes down to "too little" or "too much" for any nutrient and the most practical guideline is the DV listed on the nutrition label, in spite of its shortcomings. You can avoid the "too little" problem with a high intake every day of fruits and vegetables and some lean meat or fish and low-fat dairy products. That will cover most persons' needs for protein, calcium, vitamins and minerals.

By limiting processed meats, soft drinks and packaged foods, including baked goods, you'll avoid the Upper Limit for sodium, sugar and fat. If you must have bread and pasta, make them whole-grain.

A quality multivitamin/multimineral will fill in the gaps, especially on the days when you can't get three nutritious meals, or if you are pregnant, nursing or elderly. And you can forget about that confusing alphabet soup!

Philip J. Goscienski, M.D. is the author of Health Secrets of the Stone Age, Better Life Publishers 2005. Contact him at drphil@stoneagedoc.com.